Pilot scale degradation of mono and multi volatile organic compounds by surface discharge plasma/TiO2 reactor: Investigation of competition and synergism

Abstract

This paper mainly deals with the isovaleraldehyde degradation with the help of a nonthermal plasma surface discharge (NPSD) coupled with photocatalysis. The efficiency of NPSD reactor, for gas treatment, was studied for different binary mixtures: (1) mixture of aldehydes (Isovaleraldehyde and Butyraldehyde) and (2) mixture of aldehyde and amine (Isovaleraldehyde and Trimethylamine). A planar continuous reactor is used to investigate the effect of addition of another pollutant on the performance of oxidation process. A synergetic effect was observed by combining NPSD and photocatalysis for the degradation of mixture of pollutants. In addition, combined NPSD/photocatalysis has significantly enhanced the CO₂ selectivity, as compared to NPSD alone. This is attributed to the formation of more reactive species due to the presence of TiO₂ in the plasma discharge zone. Moreover, ozone and UV light on TiO₂, produced by plasma, have activated the surface leading to enhanced mineralization. In addition, the byproducts of each binary mixture were identified and evaluated.

Keywords: Nonthermal plasma surface discharge; Photocatalysis; Synergetic effect; VOC binary mixture.